Fabrication and characterization of electrospun human hair keratin templates

Abstract

Fibers electrospun from keratin obtained from various sources such as wool and feathers have been studied extensively, but little research has been done on keratin extracted from human hair even though it is one of the most abundant resources in the world. Thus, this study was performed with the intention to fabricate and subsequently characterize human hair keratin fibers produced by electrospinning. By blending keratin with polyethylene oxide (PEO), the processibility of the solution as well as the mechanical properties of the produced fiber can be improved. Various recipes of keratin blended with PEO were attempted, varying the solution concentration, polymer concentration, keratin concentration and incubation time. Seven successful formulations were discovered and these formulations were electrospun on a grounded collector to obtain a randomly oriented fiber mat. This fiber mat was subsequently characterized using various characterization techniques such as rheology, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and fourier transform infra-red spectroscopy (FTIR) and it was observed that the electrospun keratin fibers behave similarly to the original human keratin extract. The best formulation was determined to be obtained by mixing sodium sulfide nonahydrate (Na2S·9H2O) with a keratin: PEO ratio of 60:1. The resulting solution had the most reproducible results and had the smallest average fiber diameter. A viscosity range that could electrospin fibers with the current materials and procedures was also identified. However, as a proper fiber mat could not be produced, certain characterization techniques such as mechanical testing and contact angle tests could not be carried out. Further optimization of the parameters is necessary as the fibers obtained displayed beading in their structure. The significance of this project is to produce microfibers made from human hair keratin, mainly for biomedical applications, and to understand the behaviour of keratin fibers for further applications.